Method of coating cores



Jan. 25, 1927.

H. G. WALKER ET AL METHOD oncom'me CORES 2 Sheets-Sheet 1 Filed March 29. 1922 frwemfirs Howard 6'. Walker flfberTTMa rch Jan. 25, 1927.

H. G. WALKER ET AL METHOD OF comma coREs Filed March 29. 1922 2 SheetsSheet 2 llllll/Illll I72 yen 0m Howard 6'. M a/fier fliber? T. March Patented Jan. 25, 1927.

UNITED STATES PATENT OFFICE.

HOWARD GEORGE WALKER, OF BERWYN', AND ALBERT THOMAS MARCH, CHICAGO, ILLINOIS, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION} OF NEW YORK.

METHOD OF COATING CORES.

Application filed March 29, 1922. Serial No. 547,923.

This invention relates to a method of Briefly stated, the method consists in bringing the core and pulp into intimate relation in such manner that pulp is applied to the core and caused to cling thereto. This may be accomplished b sub ecting the core to a liquid containing t e pulp in such manner that pulp is applied to the core and caused to cling thereto due to the surface tension of the liquid in which the pulp is suspended and the felting action of the pulp. Where this method is used for coatinga core in strand form, after the pulp is applied and attached to the core as ust described, the pulp may be formed while still moist to effect both a thorough intermingling of the pulp fibers and to cause the pulp to conform 26 to the shape of the core. a

The present method may be employed to advantage for insulating electrical conductors, but it is to be understood that it is not limited to this purpose but only in so far as 30 is definedby the ap nded claims. Where the method is used or insulating electrical conductors, manila, wood, rag, cotton, esparto, jute, hemp, and asbestos pul s may be emplo ed as the coating materia but other materials than those specified may be used without departing from the spirit and scope of the present invention which contemplates in its broadest aspect the coating of any core with any pulp. The term core in strand form, as used in the specification and appended claims, refers to a 'core having the configuration resembling a fibre, hair, filament, string, small cord. or the like, or in the nature of a rope consisting of fibres, yarns or wires twisted together.

The drawin illustrate apparatus ca able of accomplishing the method as emp oyed for coating a core in strand form, the steps,

of the method consisting in first bringing the core to be coated into intimate contact with a liquid containing pulp whereby pulp is applied thereto; second, removing the core from the pulp mixtureto permit the deposited pulp to clingito the core; third, remov- E5 ing excess moisture from the pulp without detaching it from the core; fourth, forming the pulpwhile still moist so that it conforms with the shape of the core, and fifth, removmg substantially all of the moisture from the pulp so that a dry pulp coating remains ontecore. The drawings illustrate a preferred form of apparatus by which the method maylbe performed.

A means for performing the first step of the method, which consists in. applying pulp to the core, may comprise a receptacle containin the. pulp mixture and a hollow drum rotata ly mounted therein, the drum having a foraminous portion which supports the core. The level of the pulp mixture within the drum is maintained lower than the level of the mixture in the receptacle so that a circulation of pulp mixture into the drum throu h the foraminous portion is mainf taine which causes the pulp to be strained onto the foraminous portion and applied to the core supported thereon. In place of the mechanism just described for depositing the pulp on the core the wet end of a Fourdrinier machine may be employed, but any other suitable means may be used for applying the pulp to the core without departing from the spirit and scope of the present invention.

The second step of the process is performed by removing the core from the drum in such manner that it is suspended so that the pulp deposit thereon is caused to cling around the core due to gravity, the surface tension of the liquid in the pulp mixture, and the felting action of the pulp fibers.

The third step of the process, which cons sts in removing the greater portion of the liquid from the pulp on the core, may be performed by a plurality of squeezing rolls between which the core with the pulp clinging thereto is passed. It has been found deslrable toprovide a single auxiliary roll of foraminous material over which the core is passed in advance of its subjection to the squeezing rolls in order that the free liquid, so to speak, in the pulp mixture is drained off in a manner which will not cause the applied pulp to be washed off of the core. This auxiliary roll, however, maybe dispensed with if other means is rovided for removing the free liquid w ich ma in fact be removed by permitting it to rain off by gravity. The squeezing rolls referred 110 to above not only remove the greater portion of the liquid from the pulp on the core, but also form the pulp into a ribbon extending at opposite sides thereof.

The fourth step of the process, which consists in forming the pulp around the core and causing it to conform to the shape thereof, may be performed by a pair of spring pressed plates which engage the core longitudinally and at opposite sides thereof, the plates being rotated around the core. These plates in rotating wrap the edges of the ribbon, formed by the squeezing rolls, around each other and around the core so that the pulp conforms to the shape of the core. This former also causes a thorough intermingling of the fibers of the pulp and fastens it se curely t the core.

The fifth last step of the process, which consists in removing substantially all of the moisture from the pulp mixture, may i by drums over which the core thereon. is d the Sidtllll be performed with the pulp ing free liquid from the pulp deposited on the core;

Figs. 7, 8, 9 and 10 are enlarged views showing the form of the pulp coating on the core as it is delivered from the liquid containing pulp, the squeezing rolls, and former respectively Fig. 11 is :1V top plan view of the core and pulp coating shown in Fig. 8.

The apparatus disclosed for performing the process is particularly adapted for coating a core in strand form, but it is to be understood that other apparatus may be devised for coating cores in other forms and still be within the scope of the present process.

Referring now to the drawings in detail, in which like reference numerals designate similar parts throughout the several views,

the core tobe coated is fed from a supply 20, over an idler roll 21, and thence around a drum 22 which is partly submerged in a liquid containing pulp within a semi-circular trough 23. The drum 22 comprises a pair of sheet metal sides 24, Fig. 5, and a peripheral portion 25 secured thereto. The portion 25 is provided with a plurality of relatively large perforations 26 which are covered with a narrow strip of fine wire mesh 27. The core in passing around the drum lies upon the wire mesh 27 as is shown in Fig. 2. The drum 22 has a centrally dis posed tubular axle 28 which is rotatably mounted in suitable bearings 29 carried by a framework 30 which supports all the elemerits of the apparatus.

In order to apply pulp to the core as it passes over the drum 22 the pulp mixture within the drum is maintained at a lower level than that of the pulp mixture in the Qt, as indicated. by the dotted lines A respectively. This difference levels e 3i which has 1 the pulp mi):- d its discharge the tubular axle it continue "thin the drum 2i.

numpec bacla. into t uitable manner. he drum 22 car-- rice the core thereon through the tank, due to the (lllTQlQllCQ in the levels of the liquid within the drum and the tank 2 the liquid in the tank 23 will pass through the wire mesh 27 and perforations 26, straining the pulp onto the outer surface of the wire mesh, and applying pulp on the core supported thereon. In order to keep the wire mesh clean prior to its reception of the core and a new coating of pulp, it is washed by a jet of water under pressure which is supplied through a nozzle 33.

The drum 22 is rotated in the direction indicated by the arrow. The core with the coating of pulp thereon leaves the drum at the top thereof, and the force of gravity, surface tension of the liquid in the pulp mixture, and the felting action of the pulp fibers cause it to surround the core and cling to it in substantially the form shown in Fi 7 From the drum 22 the core with pulp applied thereon is passed over an auxiliary roll 34: and then between a pair of squeezing rolls 85 and 36. These rolls are rotatably mounted between a pair of brackets 37 secured to an upright standard 38 supported by the framework 30. The shaft carrying the roll 36 is driven through a pulley attached thereto which is actuated by a motor 39 in any suitable manner, as by means of the belts 40 and 41 shown. The rolls 35 and 86 preferably draw the core from the sup ply roll 20, over the drum 22, causing it to rotate, and then between them.

The auxiliary roll 34, as shown in Fig. 6, is a hollow sheet metal drum having a peripheral slot covered with a strip of fine wire mesh 42. It has been found preferable to employ the auxiliary roll 34 and to make it foraminous where it enga es the core and pulp coating thereon in or er that the free liquid, so to speak, may be strained otf away from the core and coating without causing a back flow of the liquid which would tend to wash off the pulp coating which at this stage of the process is very soft and moist and easily removed from the core. With the free liquid removed the coating has greater strength, due to a closer felting of the fibers so that when the core and coating are passed through the squeezing rolls the coating will not be torn from the core.

The squeezing rolls may be formed of rubber and forced together b means of any suitable tension means whic is adjustable to present the proper pressure on the core and pulp coating as they pass between the rolls. These rolls remove the greater portion of the liquid from the pul mixture and form the ulp into a thin rib on which extends latera 1 from each side of the core as is shown in l igs. 8 and 11. This squeezing operation also tends to mat or felt the fibers into more intimate relation, increase the tensile strength of the covering and secure it to the core.

From the squeezing rolls the core with its ribbon pulp coating is drawn through a former which wraps the projecting edges of the ribbon around the core and around each other, the appearance of the coating after it is first acted on by the former and after the forming action is completed being shown clearly in Figs. 9 and 10. The former causes a thorough intermingling of the pulp fibers and shapes the coating so that it embraces the core and conforms to the shape thereof. This step of the process forms the coating into a mass so homogeneous that upon cutting the core and coating the latter will not fray or ravel and will not become easily detached from the core.

The former, shown in detail in Figs. 3 and 4, comprises two cup shaped collars 43 and 44 held together and in spaced relation by means of rods 45. Integral with each of said collars 43 and 44 is a sleeve 46 and 46 respectively which are rotatably mount ed within suitable bearings in the standards 37 and another pair of standards 47 which are supported by the framework 30. Two plates 48 and 49 have projecting tongues which are bent around two of the rods' to pivotally support the plates in opposed relation to each other. Compression springs 50 engage the rear faces of each of the plates 48 and 49 and tend to force. them together. The springs 50 are put under the requisite compression by means of ad- 'usting screws 51 which are mounted in rackets 52 secured to the rods 45. The ends of the ]plates 48 and 49 ad'acent the squeezing ro ls 35 and 36 are ared outwardly so as to present a smooth surface tothe core and pulp coating as they pass from the said rolls through the sleeve 46 and between the forming plates 48 and 49. The core passes from the forming plates through the sleeve 46.

The plates 48 and 49 are rapidly rotated around the core and the pulp coating thereon through the medium of a pulley 18 secured to the sleeve 46, the pulley being driven by'the motor 39 through a belt 17.

The forming plates 48 and 49 wrap the projecting edges of the pulp ribbon about each other and around the core in much the same manner as though the core and pulp ribbon were rolled on a table top with the alm of the hand.

'1 e core with its formed coating is drawn from the former and subjected to a mechanism for thoroughly drying out the coating. The means shown for performing this step in the process are a pair of wide hollow drums 52 and 53 heated internally and having a plurality of grooves 53 formed thereon, Fig. 2, which receive the core, guides (not shown) being provided for directing the core over first one drum and then the other until it has traversed all of the grooves on both drums, after which it is stored on a receiving drum 54. The drums 52 and 53 are revolvably mounted in suitable bearings carried by vertical standards supported by the framework. The receiving drum 54 is also revolvably mounted in bearings carried by brackets 55 supported by the framework 30 and is driven b the motor 39 through suitable belting, the d iums 52 and 53 being driven from the drum 54 also through a suitable belting system.

Although it has been stated that the primary object of the invention is to apply a coating of pulp to a core without the use of any adhesive substance, the process herein disclosed may be used with a pulp mixture containing a sizing substance, or the pulp may be deposited on a core which has een previously treated with an adhesive agent, without departing from the spirit and scope of the present invention.

\Vhat is claimed is:

1.. A method of coating a core in strand form, consisting in subjecting the core to a liquid containing pulp in such manner that pulp .is applied thereto and then forming the pulp on the core to constitute a coating conforming with the core and retained on the core by a felting of the pulp fibres.

2. A method of coating a core in strand form, consisting in applying ulp to cause it to be attached thereto in tiie form of a ribbon and wrapping the ribbon around the core to constitute a coating surrounding the core, retained thereon by a felting of the pulp fibres.

3. A method of coating a core in strand form, consisting in subjecting the core to a pulp in such manner that pulp is applied thereto, forming the pulp on the core into a ribbon, and then wrapping the ribbon around the core to constitute a coating retained on the core by a felting of the pulp fibers.

4. A method of coating a core in strand form, consisting in applying Wet pulp to the core, squeezing the pulp on the core to remove moisture therefrom and form it into a ribbon, and then wrapping said ribbon around the core to constitute a coating conforming therewith and retained on the core by a felting of the pulp fibers.

5. A method of coating a core in strand form, consisting in attaching a ribbon of wet pulp to the core and then forming said ribbon on the core to constitute a coating surrounding the core, attached thereto by an intermingling of the pulp fibres and having'a curved outer surface.

6. A method of coating a core in strand form, consisting in attaching a ribbon of pulp to the core longitudinally thereof, and then wrapping said ribbon laterally around the core to constitute a coating surrounding the core, and conforming therewith and retained on the core by the felting of the pulp fibres.

7. A method of coating a core in strand form consisting in subjecting the core to pulp in such manner that pulp is deposited thereon, squeezing the core and the deposited pulp so that the said pulp forms a ribbon,

and then wrapping the said ribbon around the core and around itself to form a tube of felted fibers surrounding the core.

8. A method of coating a core in strand form, consisting in subjecting the core to a liquid containing pulp in such manner that pulp is applied thereto to remove free liquid? from the pulp on the core, and then forming the said pulp to constitute a coating for the core having a circular outer surface.

9. A method of coating a core in strand form, consisting in subjecting the core to a liquid containing pulp in such manner that pulp is applied thereto, removing free liquid from the pulp on the core, squeezing the core and pulp thereon so that the said pulp forms a ribbon on the core, and then wrapping the ribbon laterally around the core to constitute a coating for the core.

10. A method of coating a core in strand form, consisting in applying pulp to the core to cause it to be attached thereto in the form of a ribbon and then fabricating said ribbon into a coating surrounding the core,

. in ribbon form to the core and then fa and retained on the core by the felting of the pulp fibres.

11. A method of coating a core in strand form, consisting in applying pul to the core in the form of a ribbon and t en causing relative lateral movement between the core and said ribbon to form said ribbon into a coating surrounding the core, and retained onthe core by a felting of the pulp fibres.

12. A method of coating a core in strand form with pulp consisting in attachin pulp Ericating the said ribbon so that it constitutes a coating surroundin the core, the outer surface of the coating lieing substantially equidistant from the core at all points, and retained on the more by a felting of the pulp fibres.

13. A method of coating 0. core in strand form, consisting in applying unfinished paper, free of any adhesive material, to the core and then 'subLequentIy completing the fabrication of the unfinished paper on the core to constitute a coating surrounding the core conforming with the core and retained thereon by a felting of the pulp fibres.

14. A method of coating a core in strand form, consisting in applying a pulp ribbon to the core, and then wrapping the ribbon around the core to constitute a coating surroundin the core conforming therewith, and retained on the core by a felting of the pulp fibres.

15. A method of coating a core in strand form, consisting in subjecting the core to a liquid containing pulp in such manner that a ribbon of raid pulp is attached to the core and then formin the ribbon on the core to constitute a coating having a curved outer surface.

16. A method of coating a core in strand form with pulp, consisting in subjecting the core to a liquid containing pulp in such manner as to apply said pulp in the form of a ribbon'longitudinally of the core, and then wrapping said ribbon laterally around the core to constitute a coating therefor.

17. A method of coating a core in strand form, consisting in subjecting a moving core to a liquid containing pulp in such manner as to cause pul to be attached thereto, and then forming t is pulp so that it constitutes a coating having a curved outer surface.

18. A method of coating a core in strand form with pulp, consisting in subjecting a moving core to a liquid containing pulp in such manner that a pulpous ribbon is attached to the core, and then wrapping said ribbon around the core to constitute a coating therefor.

19. A method of coating a core in strand form, consistin in causing relative movement between the core and a liquid containing pulp in such manner as to cause pulp ion to be attached thereto and then forming the pulp so that it constitutes a coating having a curved outer surface.

20. A method of coating a core in strand form, consisting inapplying an unfinished paper ribbon to the core and then subsequently completing the fabrication of the unfinished paper ribbon and wrap ing it entirely around the core to constitute a coating therefor.

21. A method of coating a core in strand form, consisting in ap lying an unfinished paper ribbon longitudinally thereof and then subsequently completin the fabrication of the paper ribbon an wrapping it laterally around the core to constltute a coating surrounding the core.

22. A method of coating a core in strand form, consisting in applying unfinished paper free of any adhesive material in a wet state to the core and subsequently drying and completing the fabrication of the paper on the core to constitute a coating therefor having a curved outer surface and retained thereon solely by an intermingling of the pulp fibres.

23. The method of. coating a core in strand form with pulp, consisting in subjecting the core to a gulp suspended in a liquid in such manner t at pulp is applied to the core, forming the pulp so that it constitutes a coatin conformin with the core, and then removing substantially all of the suspending liquid from said coating.

24. A method of coating a core in strand form, consisting in applying unfinished paper to the core and then subsequently completing the fabrication of the unfinished paper on the core to constitute a coatin surrounding the core conforming therewit and retained on the core by a felting of the pulp fibers.

25. A method of coating a core in'strand form, consisting in applying unfinished paper in a wet state to t e core and then subsequently d ing and completing the fabrication of t e paper on the core to constitute a coating surrounding the core and retained on the core by a felting of the pulp fibers.

26. A method of coating a core consisting in a pl ing substantially individual and free pu p bres to the core and wrapping the thus applied pulp fibres around the core to constitute a coating surrounding the core retained thereon by a felting of the pulp fibres.

27. A method of coating a core in strand form consisting in applying a pulp ribbon to the core and then wrapping t e edges of the ribbon around the core by a relative rotary motion between the ribbon and core to constitute a coating conforming therewith and retained on the core by a felting of the pulp fibres.

. 28. A method of coating a core in strand form consisting in subjecting the core to a liquid containing pulp in such manner that a ribbon of pulp is applied to the core and then forming t e edges of the ribbon around the core to constitute a coating conforming therewith. I

29. A method of coating a core consisting in applying unfinished paper to the core, forming the paper applied to the core in a manner to form a ribbon having oppositely extending portions and wrapping such portions around the core in .the same direction to constitute a coating therefor.

30. A method of coating a. core in strand form consisting in collecting cellular pulp fibres on the core and then forming the pulp fibres on the core into a coating therefor,'retained solely by an intermingling of the pulp fibres.

31. A method of coating a core in strand form consisting in collecting individual cellular pulp fibres on the core and then forming the pulp fibres on the core into a coating therefor, retained by an intermin ling of the pul fibres and conforming wit the shape of t e core.

32. A method of coating :1 core in strand form, consisting in collectin cellular pulp fibres on a moving core, an then forming the pulp fibres on the core into a coating therefor, retained by a felting of the pulp fibres.

33. The method of coating '9. core in strand form with pulp, consistin in subjectin the core to a pulp su ended in a liqui in such manner that pu p is ap lied to the core, removing the core with t e' pulp a plied thereto from the liquid, forming t e ulp so that it constitutes a coating conorming with the core and then removing substantially all of the suspended liquid from said coating.

'34. A method of coating a core in strand form, consisting in subjecting the core to a pulp in such a manner that pul is applied thereto, forming the pulp on t e core into a thin ribbon extending to opposite sides of the core and then wrapping the ribbon around the core to constltute a coating retained on the core by a felting of the pulp fibres.

35. A method of coating a core in strand form consisting in subjecting the core to a pulp in such manner that pulp1 is applied thereto, forming the pulp on t e core into a thin ribbon extending to opposite sides of the core and then wrapping the ribbon around the core to constitute a coating for the core.

36. A method of coating a core in strand form consisting in causing relative movement between the core and a liquid contain ing pulp in such a manner as to cause pulp to be attached thereto, and forming the pulp so that it constitutes a coating having a substantially circular outer surface.

37. A method of coating an electrical conductor consisting in subjectin said conductor to a liquid containing pu p in such a. manner that pulp is applie t ereto, pressing the thus applied pulp to form a ribbon and. forming said ribbon of pulp into a coating threfor. p

In witness whereof, we hereunto subscribe 10 our names this 25th day of March A. D., 1922.

HOWARD GEORGE WALKER. ALBERT THOMAS MARCH. 

